The invention relates to a substrate for an electronic circuit, the electronic circuit carrying at least one contact pad, the substrate comprising an insulating element housing the electronic circuit and carrying, on an external side, a conductive layer defining at least one contact region, said contact pad at least provided being connected to said contact region.
A substrate of this type is well known in the field of chip cards of the credit card type or other types; described for example in the document U.S. Pat. No. 4,211,919, and used by a user to obtain products or services, or to access a location. In this case, several contact pads are provided, which enable the card to cooperate with a card reading terminal into which it is inserted. The substrate is inserted into a recess produced in the card, and is mounted to it, particularly by bonding.
A known means of fraud, for removing any information identifying the legitimate card holder affixed to the surface of the card (such as a number, an inscription or a photo), consists of removing the substrate from an authentic card and attaching it to a fraudulent card. To do this, it is necessary to detach the substrate without damaging it.
The object of the invention is to provide the means for making the fraudulent operation for removing the substrate detectable, or even inoperable.
According to the invention, the substrate is characterized in that it comprises at least one fragile zone disposed in the insulating element. Thus, during an attempt to remove the substrate in which stress is exerted on it, the substrate will be damaged due to the presence of the fragile zone; the fragile zone will cause deformations which can be seen in the conductive layer; these same deformations will often result in making the substrate inoperable, since they will have caused a break in the electronic circuit or in its connection with the contact region.